This invention relates to a door module of a vehicle door.
Such door module includes a carrier plate and a drive unit arranged on the carrier plate for driving a power-operated adjustment device of the door module. The carrier plate can constitute an integrated assembly carrier for carrying different functional components of a vehicle door, for example a window lifter unit, a door lock, a loudspeaker or other functional components of the vehicle door. The drive unit for example serves for driving the window lifter and for this purpose for example includes an electric motor for the motorized drive of a window pane guided along guide rails.
A carrier plate of such door module extends in a planar manner and for mounting the door module on a vehicle door for example is connected with a door inner panel of the vehicle door. Nowadays, the carrier plate generally is formed of plastics and carries the drive unit connected via one or more fastening points.
In operation of the drive unit, components, for example movable parts of the electric motor or driven transmission parts, necessarily are set in motion. These movements of the drive unit or its components are also introduced into the carrier plate as vibrations via the coupling fastening points and excite the carrier plate to vibrate. As a result of this excitation, sound waves (also referred to as structure-borne sound) are generated, which can be perceived in the vehicle interior and, when the frequency range of the excitation vibrations overlaps with the natural resonance frequencies of the vehicle door arrangement, can even be amplified and possibly lead to a disturbing vibration and rattling.
In such door modules it is desirable to inhibit or at least reduce a sound generation and a sound propagation at least to such an extent that it is no longer perceived as disturbing for a vehicle occupant in the vehicle.
In a door module known from DE 10 2008 048 236 A1, a drive unit is coupled with a carrier plate via three fastening points, wherein as acoustic decoupling means for attenuating the excitation regions with increased elasticity are provided on the carrier plate around the drive unit or around each of the fastening points of the drive unit. For this purpose, circumferential rings of wave-like shape are provided around the drive unit or around the fastening points, which in their rigidity are softer than the remaining portions of the carrier plate and hence do not transmit vibrations of the drive unit to the carrier plate, or at least in an only strongly attenuated manner.